The disclosure relates to a hydroelastic bearing, in particular for use in a motor vehicle. The hydroelastic bearing can for example be used to bear a subframe or a wheel connecting rod, in particular a control arm. The hydroelastic bearing can also be used as a bearing for aggregates, as well as to bear the oscillating mass of a mass damper.
The hydroelastic bearing is generally used when a relative movement of a component subject to oscillations such as a motor vehicle component is to be approved for the body and dampened. The hydroelastic bearing offers restorative spring force from the use of elastomer material, as well as damping force which is actively generated in the bearing by means of dissipation loss.
In general, the hydroelastic bearing has a spring function member and an outer sleeve coupled to the spring function member. The spring function member has an inner mounting connection by means of which the bearing is to be mounted on a component subject to a vibration load, such as the body of a motor vehicle. The outer sleeve is generally fastened to the motor vehicle part that is to be connected to the motor vehicle body. The spring function member is mounted in the outer sleeve and is connected by an outer mounting connection of the spring function member to the outer sleeve. A reverse connection of the spring function member to the motor vehicle body and the motor vehicle component can also be considered. A spring body of the spring function member couples the mounting connections to each other in order to permit a relative movement between the mounting connections, or respectively between the inner mounting connection and the outer sleeve. The spring body at least partly borders two working chambers for holding a damping fluid. The working chambers can communicate fluidically with each other by a damping channel to permit an exchange of fluid between the working chambers given a specific, relative deflection of the inner mounting connection and outer sleeve and changes in volume to the working chamber caused thereby, and to generate dissipation loss by the flow between the working chambers.
The damping properties can be established by adjustments to the flow resonance of the damping channel and the working chambers. With conventional hydroelastic bearings, the hydroelastic bearing, despite such an adjustment of the damping properties, can manifest high dynamic rigidity due to the flow resonances in the damping channel within a specific excitation frequency range, and at specific excitation amplitudes. This can be the case in particular at medium-high excitation frequencies and simultaneous low amplitudes. Medium-high excitation frequencies can be excitation frequencies within a range between approximately 20 Hz and approximately 300 Hz, which is particularly relevant with regard to the development of noise by a road. By low amplitudes, such amplitudes are meant that normally occur in this medium high-frequency range of a road.
To prevent dynamic rigidification of the hydroelastic bearing at low amplitudes, isolators can be provided in the hydroelastic bearing. Generally, the isolator is arranged in an additional decoupling channel, wherein the decoupling channel also connects the working chambers, and wherein the decoupling channel is typically designed with a diameter that is larger and a length that is smaller than the damping channel. The isolator is designed flexible, or respectively movable, and is arranged in the decoupling channel. The isolator ensures that at low excitation amplitudes, the damping fluid can flow in and out of the decoupling channel, whereby at low excitation amplitudes, the working chambers can be isolated, and dynamic rigidification from the flow resonances in the damping channel can be prevented. At high excitation amplitudes, the isolator contrastingly closes the decoupling channel so that the damping fluid flows through the damping channel.
Until now, however, no isolation apparatus has been developed that permits a satisfactory adjustment of the dynamic properties of the hydroelastic bearing.